ask for directions often, confirm and reconfirm. 99% of the way is de freeeeente nada mas but easy to get sidetracked. travel during the day as much as possible. fill up every chance you get. definitely fill up in chiclayo. they are improving roads here in the north and some are now even two lane. watch out for pendejos driving in the middle of the road. road tripping peru is awesome, just be prudent about speeds in the north north. and unexpected rompemuelles.
a trick, if the police try to stop you, dont pull over right away, but coast a few hundred meters past, usually they wont walk that far to try and get the arbitrary road tax.
sometimes strong winds and zonas de dunas will occur, be careful. use extreeeeeme caution in amazonas dept.